there is a mastery hack now. for sas4  it gives u like 16k xp for all catergorys even if u didnt do anything in that game., i got all my things to mastery 4, very close to 5 :)
 

LoL, banned?   You can't get banned using mastery hack alone.  You CAN get banned only if you almost  MAXED out masteries and you are still using it by  forcing to lvl up more, that will get you banned.  

If you want the masteries even faster, change the value to this instead of the value haenawolf provides: 2d 12 02 02 02 02 02 02 02

That should get you all masteries near instantly.

Edit:  I should mention if you are on NK, you should go through your profile and delete all mentions of getting all of those level 5 masteries at the same time from your activity feed so someone following you doesn't report you and get you banned.

You should note that haenawolf's change value should survive a patch, where the value I provided is only good for this patch as the integer value that "12" represents will change in a patch. However currently that 12 represents a far greater value than 16000. 12 represents 999,999.

If you want to dial it back a bit, you can change it to "2d 06 02 02 02 02 02 02 02" '06' represents 65,535. Not as high of a jump, but still a much larger jump than 16k.

 

you are accessing integers by index. Those will change on update so it's quite a gamble and can behave unexpectely, so given there is a lot of room to maneuver you could as well do something like that 25 e8 07 24 64 a2 02 02 02 to have the amount fixed to 100.000. 
 

Everything works fine to me.
 

I don't know whether masteries are checked by the system itself. I don't think they are, meaning that you'll only get banned if you're reported after somebody's taking a peek at your statistics and notices your masteries are far too high.